Front Splitter and Bumper combo

johnxxx · 11-04-2020, 07:43 PM

Quote:

Originally Posted by victorofhavoc

Is the bottom of that stillen bumper flat across and back? Meaning does a splitter fit flush against it if it was just a flat board?

I've seriously been considering buying honeycomb and 1/8" birch to make my own structure, but if alumilite is as cheap as some have come by that might be a better option. I am curious how much the racebred splitters weigh since they're a birch honeycomb.

Thanks for all the great options and suggestions everyone! This will be a fun off season project. Can't wait to get this car back out there next year!!

.

Ps, if anyone lives near tulsa, ok, there's a mustang club event at hallett this weekend. I wanted to make it, but my wife has to work and that means I'm watching our baby

.

The splitter itself is semi rigid yet somewhat flexible. It's CNC machined aluminum composite. Here's a photo of the underside. The stillen bumper itself curves upward that small 5 degrees and this comforms to it nicely.

These guys over at Ventus Auto Works can do custom splitters or any variation you need as well. Not affiliated with them... just a one time customer helping out a forum member if you're interested.

Hotrodz · 11-04-2020, 09:02 PM

This guy is an aero geek and freaking fast on the track. Here is his take on splitter materials.

https://youtu.be/LGCKGv2K4_M

Sent from my SM-G965U using Tapatalk

victorofhavoc · 11-04-2020, 09:24 PM

Quote:

Originally Posted by Hotrodz

This guy is an aero geek and freaking fast on the track. Here is his take on splitter materials.

https://youtu.be/LGCKGv2K4_M

Sent from my SM-G965U using Tapatalk

Hmm, I wonder how he feels about the wood honeycomb sandwich materials. Carbon is definitely the best if you go with a nomex sandwich. I've worked that stuff before and it's really easy. Problem is at splitter size the pricing is crazy. You can make your own 4x8 sheet of the stuff for around 600$, though, but you need a perfectly level surface.

///maestro · 11-06-2020, 01:50 PM

I have not weighed the splitter I made. It actually wasn't even a splitter, it was just a chassis mounted undertray. Mainly made it for 2 reasons:

A: Test the chassis mounting
B: protect my oil pan and bumper from getting destroyed because I used to do street driving.

That being said, I street drive it maybe 2% of the time, very seldom. The race group/class I compete in restricts aftermarket aero, so I will be removing my chassis mount and maybe saving it for the future if I bump up a class. You may want to look into a racing league (ie. Gridlife, NASA, Global Time Attack) and build your car to a specific class spec (if you haven't already).

Regarding the chassis mounting hardware, I purchased the battle aero mounting brackets. They are OK but under heavy load, I do think the two mounting points are not enough and cause flex in the splitter. I would make 4 additional mounting points on a splitter with the Battle Aero chassis mounting hardware (2 in the middle, and 1 on each far side).

See image of their product:

victorofhavoc · 11-06-2020, 02:54 PM

Quote:

Originally Posted by ///maestro

I have not weighed the splitter I made. It actually wasn't even a splitter, it was just a chassis mounted undertray. Mainly made it for 2 reasons:

A: Test the chassis mounting
B: protect my oil pan and bumper from getting destroyed because I used to do street driving.

That being said, I street drive it maybe 2% of the time, very seldom. The race group/class I compete in restricts aftermarket aero, so I will be removing my chassis mount and maybe saving it for the future if I bump up a class. You may want to look into a racing league (ie. Gridlife, NASA, Global Time Attack) and build your car to a specific class spec (if you haven't already).

Regarding the chassis mounting hardware, I purchased the battle aero mounting brackets. They are OK but under heavy load, I do think the two mounting points are not enough and cause flex in the splitter. I would make 4 additional mounting points on a splitter with the Battle Aero chassis mounting hardware (2 in the middle, and 1 on each far side).

See image of their product:

So I'm talking to Professional Awesome about getting a custom cut piece from the racebred honeycomb birch and getting their mounting hardware since it's quick release (trailered everywhere). I'll have to do some fab work myself, but it shouldn't be too bad. Air dam will be fun...

I did the math on 10mm alumalite (which I read was recommended for splitter use over the 6mm due to flex) in the same square footage size as the birch splitter and there's a pretty massive weight advantage. 10 lbs vs 20 lbs. Carbon when done well is typically around 6lbs...so that's pretty solid.

victorofhavoc · 11-11-2020, 08:18 AM

So after more research on the racebred splitter, like most others it's a marine grade plywood that can be purchased in 4x8 sheets for 60-80$. This really doesn't seem worth it to me to spend 400$ plus 75 shipping on something I can make myself for <100$ and a couple hours of time. Granted, it's proving more difficult than I thought to find a source of marine grade birch ply.

I've been pricing out supplies to just make my own dry carbon splitter, and it's really not so bad. For that same 400$ I can get the majority of stuff I need and the work itself is pretty easy if you've ever worked with carbon or fiberglass before.

Anyone know of decent places to source marine grade ply, marine grade wood composites, or has anyone made their own carbon pieces?

victorofhavoc · 11-24-2020, 05:13 PM

Updated the OP... Looks like I'm going down the make your own dry carbon rabbit hole... I should be able to pop out splitters at 230-320$ consumables cost depending on carbon or Kevlar design, quality, and color.

2011 Nismo#91 · 12-08-2020, 05:34 AM

Quote:

Originally Posted by victorofhavoc

Updated the OP... Looks like I'm going down the make your own dry carbon rabbit hole... I should be able to pop out splitters at 230-320$ consumables cost depending on carbon or Kevlar design, quality, and color.

You have access to an autoclav big enough for a splitter?

victorofhavoc · 12-08-2020, 03:28 PM

Quote:

Originally Posted by 2011 Nismo#91

You have access to an autoclav big enough for a splitter?

You don't need an autoclave unless you're using an epoxy resin that requires high temp cure or you're trying to drastically accelerate your cure process. Prepreg also often requires a high temp or autoclave cure due to the nature of producing a carbon which contains a gelled resin.

The resin I chose is high impact and high temp (325*) with a 1 hour pot life and should take approximately 24 hrs to cure at room temp. The same epoxy can be cured for 18 hrs at room temp and 6 hrs at 185* to have a 450* temp resistance, but that also requires a different catalyst.

Edit: If you're referring to the use of "dry carbon" vs "wet carbon" in context, technically laying down your own resin layers is considered "wet" by the newer definitions but adding in the vacuum process and layering the resin/epoxy with a final higher cure temp also produces a "dry carbon". The goal is to get to 40% resin by weight to carbon and most well done vacuumed setups can get you pretty close. When I first worked with carbon in 2007 anything with resin content below 60% was considered "dry carbon".

victorofhavoc · 12-07-2020, 10:38 AM

In the past few weeks I made some time to order some carbon, do a good amount of reading on aero theories (I have a very good conceptual and practical understanding of physics in my educational background), and start putting a few things together.

Fun stuff first, I ordered all of the carbon and carbon Kevlar I plan to use for the splitter and it arrived very quickly! I also ordered some high temp and high impact epoxy resin with a 1 hour pot life. This is the same stuff that Boeing uses, and the same stuff some of the indy car builders use. It's only a 1 hr life so I will have to move very quickly, and it also requires a higher temp cure time. This resin is the only part I'm nervous about and resin is really the key to the whole thing! I bought a black commercial grade twil carbon since it was only 12$ per yard and weighs 203 grams per square meter. It will form the two base layers of structural carbon to my splitter. I also got the digital red camo carbon Kevlar, which is an absolutely beautiful product in person and really cannot be described or photographed well. It will form my top layer and should be the most durable. As I wear through it and black carbon is exposed I should be able to make repairs with my left over material!

I got the bumper off and made a cardboard air dam to start. I'm still not 100% certain how to best cut an air dam to shape that will fit the curves of the front bumper, but I traced what I had to make a basic start and it's starting to resemble a splitter!

Moving on, I got some hardware to mount up my professional awesome quick releases. It will be two u bolts per quick release with two angle brackets so that the u bolts clamp to the crash beam, the L brackets are bolted to the u bolts, and the quick releases then adjust up and down the L bracket as well as allowing the adjustment up and down the u bolt.

If anyone else plans to jump down a similar rabbit hole, I highly recommend looking at professional awesome's diy front aero page, https://professionalawesome.com/diy-downforce/ . I did a tremendous amount of reading about a lot of other aero concepts after using their page as a starting point. There's really a lot to go down, but one of the key aspects which I didn't realize until I read about it, is that the Battle Aero wing that came with my car had endplates facing the wrong way

. The meat of the plate should always be at the front of the wing. Also, the wing shape isn't ideal, but it's not bad. It's prone to a bit more drag than a typical wing used in motorsport with data behind it, and there's a lot of improvement to be had from going to a dual element air foil, so at some point I guess I might even try my hand at a carbon wing... Pictured below is the CORRECT orientation of the endplates. This should help reduce a tremendous amount of drag and improve downforce at the outsides of the wing. This is especially needed given the width of the Z's front and rear fenders which greatly disturb the air flow underneath the ends of the air foil.

I measured out the radiator and the front grill intake as well. As it turns out the front grill intake (the functional parts not the plastic) are sized exactly 1/3rd of the surface area of the cooling stack! That's exactly how it should be! Who would have guessed nissan engineers knew what they were doing!? Now I just need to cut out the obstructive plastic and create a curved intake panel that will reach to the edges of the radiator to seal all that air in and force it through the cooling stack. With some louvres this should help keep all temps greatly in check and reduce underhood pressure at speed, which will lead to more downforce! I also plan to use the oem vertical DRL as an intake for the brake ducts. I checked and a shopvac general purpose suction end fits the size, so I may try to glue one on and see how it goes! Likely the intake will have to be downsized eventually, but that's not so hard to do...

So here's the major problem at the moment!! I bought a venturi vac to generate my vacuum suction for the resin catch which then sucks from the bag. I hooked everything up and I was missing several fittings. After a trip to home depot racing, I got all the fittings I needed and test the vac. It immediately pulled 27"hg but the cost was high... It needed a minimum 55 psi @ 3.5 cfm to maintain that vac and while my compressor can run 5cfm at 90psi, it only runs 3.5 cfm @ 165 psi and coincidentally that's where it got stuck on recharge and would run perpetually! It obviously would never get back to its 200psi full charge. There are other venturi that perform better and generate 1atm or 29"hg at only 0.5 cfm, but those cost as much as a knockoff vac pump on Amazon, so I went ahead and bought the vac pump. It should arrive this week for more testing!

Rusty · 12-07-2020, 11:22 AM

Steep learning curve.

Keep in mind the suspension travel. You don't want the splitter to low to where it scraps all the time. I've hit a G out at speed and scrapped the whole bottom of the splitter.

Hotrodz · 12-07-2020, 12:28 PM

Agreed, I did not have splitter supports and just lifting at 140 mph brought the splitter in contact with the road. Not good!

Sent from my SM-G965U using Tapatalk

Hotrodz · 12-07-2020, 12:30 PM

Also, if you email those guys at Profesional Awesome Racing they may provide you with free advice. They have help me out a ton with my stuff.

Sent from my SM-G965U using Tapatalk

victorofhavoc · 12-07-2020, 01:21 PM

Quote:

Originally Posted by Hotrodz

Also, if you email those guys at Profesional Awesome Racing they may provide you with free advice. They have help me out a ton with my stuff.

Sent from my SM-G965U using Tapatalk

Yep, I've been working with them actually! They've given me some good advice so far and I have their front support hardware that has titanium pucks on the bottom to protect the splitter in certain impacts. I'll likely add a couple more titanium skids on the sides. They're not cheap at 30$ a pop, but not the worst either.

My measurements so far indicate I will be a bit over 3 inches from splitter to ground. The front springs are 14k and dampening is currently a bit on the soft end. I believe I'll have to up compression and rebound both a bit to account for the splitter but we'll see.

Did my images post for anyone else? I'm looking at my post now and don't see them at all...

Hotrodz · 12-07-2020, 01:37 PM

Cool, the pictures did not post.

11-04-2020, 09:02 PM	#2 (permalink)
Hotrodz A True Z Fanatic Join Date: Aug 2012 Location: NW, AZ Posts: 9,330 Drives: 10 Nissan 370z Nismo Rep Power: 2684386	This guy is an aero geek and freaking fast on the track. Here is his take on splitter materials. https://youtu.be/LGCKGv2K4_M Sent from my SM-G965U using Tapatalk street2soul, Rusty and johnxxx like this. __________________ *Fast Intentions TT Installed and Tuned by Seb at SpecialtyZ 610whp 560tq:\|Fast Intentions 3" TT-TDX*\|SpecialtyZ/Fast Intentions 72 Row Oil Cooler\|SZ 6 Puck Clutch & Flywheel\|3GsCustoms\|Z1\|Wavetrac\|Hotchkis\|Whiteline \|Blitz\|Fortune Auto 500\|Fujimura\|SPL\|H&R\|TK\|TWM\|RPM Rollbar\|Sparco\|Next Level Performance\|TrackSpec\|AeroFlow Dynamics\|Pioneer\|

11-06-2020, 01:50 PM	#4 (permalink)
///maestro Track Member Join Date: Dec 2014 Location: Grand Rapids, MI Posts: 530 Drives: 11' 370z\|09' BMW M3 Rep Power: 13	I have not weighed the splitter I made. It actually wasn't even a splitter, it was just a chassis mounted undertray. Mainly made it for 2 reasons: A: Test the chassis mounting B: protect my oil pan and bumper from getting destroyed because I used to do street driving. That being said, I street drive it maybe 2% of the time, very seldom. The race group/class I compete in restricts aftermarket aero, so I will be removing my chassis mount and maybe saving it for the future if I bump up a class. You may want to look into a racing league (ie. Gridlife, NASA, Global Time Attack) and build your car to a specific class spec (if you haven't already). Regarding the chassis mounting hardware, I purchased the battle aero mounting brackets. They are OK but under heavy load, I do think the two mounting points are not enough and cause flex in the splitter. I would make 4 additional mounting points on a splitter with the Battle Aero chassis mounting hardware (2 in the middle, and 1 on each far side). See image of their product: Rusty, Hotrodz and johnxxx like this. __________________ Gallo24 swapped 370z Instagram: @z34_motorsport Last edited by ///maestro; 11-06-2020 at 01:52 PM.

11-11-2020, 08:18 AM	#6 (permalink)
victorofhavoc Base Member Join Date: Oct 2011 Location: Kansas City Posts: 230 Drives: 2014 370z Rep Power: 15	So after more research on the racebred splitter, like most others it's a marine grade plywood that can be purchased in 4x8 sheets for 60-80$. This really doesn't seem worth it to me to spend 400$ plus 75 shipping on something I can make myself for <100$ and a couple hours of time. Granted, it's proving more difficult than I thought to find a source of marine grade birch ply. I've been pricing out supplies to just make my own dry carbon splitter, and it's really not so bad. For that same 400$ I can get the majority of stuff I need and the work itself is pretty easy if you've ever worked with carbon or fiberglass before. Anyone know of decent places to source marine grade ply, marine grade wood composites, or has anyone made their own carbon pieces? __________________ Had a 2010 WRX- boy was it quick in a straight line, got a 2014 Z- man is she grippy in the corners-- then left the Z and later got a GTI, now back in an 09 racecar Z!

11-24-2020, 05:13 PM	#7 (permalink)
victorofhavoc Base Member Join Date: Oct 2011 Location: Kansas City Posts: 230 Drives: 2014 370z Rep Power: 15	Updated the OP... Looks like I'm going down the make your own dry carbon rabbit hole... I should be able to pop out splitters at 230-320$ consumables cost depending on carbon or Kevlar design, quality, and color. JARblue, DarkJak, Rusty and 3 others like this. __________________ Had a 2010 WRX- boy was it quick in a straight line, got a 2014 Z- man is she grippy in the corners-- then left the Z and later got a GTI, now back in an 09 racecar Z!

12-07-2020, 10:38 AM	#10 (permalink)
victorofhavoc Base Member Join Date: Oct 2011 Location: Kansas City Posts: 230 Drives: 2014 370z Rep Power: 15	In the past few weeks I made some time to order some carbon, do a good amount of reading on aero theories (I have a very good conceptual and practical understanding of physics in my educational background), and start putting a few things together. Fun stuff first, I ordered all of the carbon and carbon Kevlar I plan to use for the splitter and it arrived very quickly! I also ordered some high temp and high impact epoxy resin with a 1 hour pot life. This is the same stuff that Boeing uses, and the same stuff some of the indy car builders use. It's only a 1 hr life so I will have to move very quickly, and it also requires a higher temp cure time. This resin is the only part I'm nervous about and resin is really the key to the whole thing! I bought a black commercial grade twil carbon since it was only 12$ per yard and weighs 203 grams per square meter. It will form the two base layers of structural carbon to my splitter. I also got the digital red camo carbon Kevlar, which is an absolutely beautiful product in person and really cannot be described or photographed well. It will form my top layer and should be the most durable. As I wear through it and black carbon is exposed I should be able to make repairs with my left over material! I got the bumper off and made a cardboard air dam to start. I'm still not 100% certain how to best cut an air dam to shape that will fit the curves of the front bumper, but I traced what I had to make a basic start and it's starting to resemble a splitter! Moving on, I got some hardware to mount up my professional awesome quick releases. It will be two u bolts per quick release with two angle brackets so that the u bolts clamp to the crash beam, the L brackets are bolted to the u bolts, and the quick releases then adjust up and down the L bracket as well as allowing the adjustment up and down the u bolt. If anyone else plans to jump down a similar rabbit hole, I highly recommend looking at professional awesome's diy front aero page, https://professionalawesome.com/diy-downforce/ . I did a tremendous amount of reading about a lot of other aero concepts after using their page as a starting point. There's really a lot to go down, but one of the key aspects which I didn't realize until I read about it, is that the Battle Aero wing that came with my car had endplates facing the wrong way . The meat of the plate should always be at the front of the wing. Also, the wing shape isn't ideal, but it's not bad. It's prone to a bit more drag than a typical wing used in motorsport with data behind it, and there's a lot of improvement to be had from going to a dual element air foil, so at some point I guess I might even try my hand at a carbon wing... Pictured below is the CORRECT orientation of the endplates. This should help reduce a tremendous amount of drag and improve downforce at the outsides of the wing. This is especially needed given the width of the Z's front and rear fenders which greatly disturb the air flow underneath the ends of the air foil. I measured out the radiator and the front grill intake as well. As it turns out the front grill intake (the functional parts not the plastic) are sized exactly 1/3rd of the surface area of the cooling stack! That's exactly how it should be! Who would have guessed nissan engineers knew what they were doing!? Now I just need to cut out the obstructive plastic and create a curved intake panel that will reach to the edges of the radiator to seal all that air in and force it through the cooling stack. With some louvres this should help keep all temps greatly in check and reduce underhood pressure at speed, which will lead to more downforce! I also plan to use the oem vertical DRL as an intake for the brake ducts. I checked and a shopvac general purpose suction end fits the size, so I may try to glue one on and see how it goes! Likely the intake will have to be downsized eventually, but that's not so hard to do... So here's the major problem at the moment!! I bought a venturi vac to generate my vacuum suction for the resin catch which then sucks from the bag. I hooked everything up and I was missing several fittings. After a trip to home depot racing, I got all the fittings I needed and test the vac. It immediately pulled 27"hg but the cost was high... It needed a minimum 55 psi @ 3.5 cfm to maintain that vac and while my compressor can run 5cfm at 90psi, it only runs 3.5 cfm @ 165 psi and coincidentally that's where it got stuck on recharge and would run perpetually! It obviously would never get back to its 200psi full charge. There are other venturi that perform better and generate 1atm or 29"hg at only 0.5 cfm, but those cost as much as a knockoff vac pump on Amazon, so I went ahead and bought the vac pump. It should arrive this week for more testing! Rusty and Hotrodz like this. __________________ Had a 2010 WRX- boy was it quick in a straight line, got a 2014 Z- man is she grippy in the corners-- then left the Z and later got a GTI, now back in an 09 racecar Z! Last edited by victorofhavoc; 12-08-2020 at 03:35 PM.

12-07-2020, 11:22 AM	#11 (permalink)
Rusty A True Z Fanatic Join Date: Dec 2011 Location: Fayettenam,Pennsyltucky Age: 70 Posts: 35,571 Drives: 2011 Nismo GM 6M Rep Power: 2684440	Steep learning curve. Keep in mind the suspension travel. You don't want the splitter to low to where it scraps all the time. I've hit a G out at speed and scrapped the whole bottom of the splitter. Hotrodz likes this. __________________ 浪人 - 殺し屋 "The Difficult Anytime, The Impossible By Appointment Only" http://www.the370z.com/members-370z-...o-journal.html

12-07-2020, 12:28 PM	#12 (permalink)
Hotrodz A True Z Fanatic Join Date: Aug 2012 Location: NW, AZ Posts: 9,330 Drives: 10 Nissan 370z Nismo Rep Power: 2684386	Agreed, I did not have splitter supports and just lifting at 140 mph brought the splitter in contact with the road. Not good! Sent from my SM-G965U using Tapatalk Rusty likes this. __________________ *Fast Intentions TT Installed and Tuned by Seb at SpecialtyZ 610whp 560tq:\|Fast Intentions 3" TT-TDX*\|SpecialtyZ/Fast Intentions 72 Row Oil Cooler\|SZ 6 Puck Clutch & Flywheel\|3GsCustoms\|Z1\|Wavetrac\|Hotchkis\|Whiteline \|Blitz\|Fortune Auto 500\|Fujimura\|SPL\|H&R\|TK\|TWM\|RPM Rollbar\|Sparco\|Next Level Performance\|TrackSpec\|AeroFlow Dynamics\|Pioneer\|

12-07-2020, 12:30 PM	#13 (permalink)
Hotrodz A True Z Fanatic Join Date: Aug 2012 Location: NW, AZ Posts: 9,330 Drives: 10 Nissan 370z Nismo Rep Power: 2684386	Also, if you email those guys at Profesional Awesome Racing they may provide you with free advice. They have help me out a ton with my stuff. Sent from my SM-G965U using Tapatalk Rusty likes this. __________________ *Fast Intentions TT Installed and Tuned by Seb at SpecialtyZ 610whp 560tq:\|Fast Intentions 3" TT-TDX*\|SpecialtyZ/Fast Intentions 72 Row Oil Cooler\|SZ 6 Puck Clutch & Flywheel\|3GsCustoms\|Z1\|Wavetrac\|Hotchkis\|Whiteline \|Blitz\|Fortune Auto 500\|Fujimura\|SPL\|H&R\|TK\|TWM\|RPM Rollbar\|Sparco\|Next Level Performance\|TrackSpec\|AeroFlow Dynamics\|Pioneer\|

12-07-2020, 01:37 PM	#15 (permalink)
Hotrodz A True Z Fanatic Join Date: Aug 2012 Location: NW, AZ Posts: 9,330 Drives: 10 Nissan 370z Nismo Rep Power: 2684386	Cool, the pictures did not post. Rusty likes this. __________________ *Fast Intentions TT Installed and Tuned by Seb at SpecialtyZ 610whp 560tq:\|Fast Intentions 3" TT-TDX*\|SpecialtyZ/Fast Intentions 72 Row Oil Cooler\|SZ 6 Puck Clutch & Flywheel\|3GsCustoms\|Z1\|Wavetrac\|Hotchkis\|Whiteline \|Blitz\|Fortune Auto 500\|Fujimura\|SPL\|H&R\|TK\|TWM\|RPM Rollbar\|Sparco\|Next Level Performance\|TrackSpec\|AeroFlow Dynamics\|Pioneer\|

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